<template>
  <div>
    <div v-for="(item,index) in arr" :key="index">
        <input type="checkbox" :value="item" name="" id="" v-model="newArr"  @change="sumFn">{{item}}
    </div>

    你选中的元素，累加的值和为：{{sum}}
  </div>
</template>

<script>
export default {
  data () {
    return {
      arr: [9, 15, 19, 25, 29, 31, 48, 57, 62, 79, 87],
      newArr: [],
      sum: 0
    }
  },
  methods: {
    sumFn () {
      this.sum = this.newArr.reduce((sum, item) => (sum += item), 0)
    }
  }
}
</script>

<style>

</style>
